This invention relates to a digital video switching apparatus (switcher) for selecting and outputting a desired digital video signal from among a plurality of input digital video signals. More particularly, it relates to a digital video switcher handling both the digital video signal having the data rate for luminance and chrominance signals of 4:2:2 and the digital video signal having the data rate for luminance and chrominance signals of 4:4:4.
There has generally been known a digital video switcher handling a D1-format digital video signal having the data rate for the luminance signal Y and the chrominance signals U and V of 4:2:2, referred to herein as the 4:2:2 digital video signal. It is not possible with this type of the digital video switcher to process a digital video signal having the Y:U:V ratio of 4:4:4, referred to herein as the 4:4:4 digital video signal, because its internal signal processing hardware, such as a wipe or a chroma key, has the capability of processing only the 4:2:2 video signal. It is however desired of such digital video switcher to be capable of processing the 4:4:4 digital video signal as the source video signal as well.